the fbi has joined the search for 10-year-old jessica ridgeway, last seen leaving for school yesterday morning. she never arrived. abc's clayton sandell is in colorado this morning and on this breaking story. clayton? >> reporter: dan, good morning to you. right now, at least 50 police officers, including the fbi, are continuing their search, overnight, using bloodhounds in temperatures that were near-freezing. still, there has been no sign of little jessica ridgway. a desperate search under way for a 10-year-old last seen nearly 24 hours a ago. the last time anyone saw jessica ridgeway was 8:30 friday morning. she left home to walk three blocks from her westminster, colorado, home to meet friends for a walk to school, a route she did every day. but she never got there. when jessica didn't show up for class, the school called her home. but jessica's mother, who works the overnight shift at a tech company, was asleep. she didn't get the message, which delayed her calling police for nearly eight hours. >> when we start with a delay as substantial as this, the distance she could have wand